Toward Quantum Computing with Molecular Magnets: Studies of Spin Dynamics in a Radiation Field

EIA-0218469Jonathan R. FriedmanAmherst College Toward Quantum Computing with Molecular Magnets; Studies of Spin DynamicsThe viability for using molecular magnets as qubit，the processing element of quantum computers through using pulsed microwave and millimeter wave radiation to perform quantum operations on these systems of spin states. 在此过程中，我们还研究了在低于几开尔文的温度下磁矩反转的隧穿机制，并通过一系列实验测量了辐射对分子磁体磁弛豫的影响.这些实验包括光子辅助弛豫，当辐射帮助分子的自旋反转方向时发生，拉比振荡的反转概率与辐射脉冲持续时间，以及由一系列辐射脉冲产生的自旋态的量子叠加的自由进动。 这些实验的目的是提供一个测量激发自旋态的退相干时间，这是决定分子磁体是否可以用作量子比特的关键参数。 该项目还在研究减轻由于偶极与邻近分子、核自旋和缺陷的相互作用而引起的非均匀加宽效应的方法。该项目对量子计算和信息存储领域具有潜在的影响。它还促进了本科生的教育，特别是妇女和少数民族等代表性不足的群体。

EIA-0218469Jonathan R. FriedmanAmherst CollegeToward Quantum Computing with Molecular Magnets; Studies of Spin DynamicsThe viability for using molecular magnets as qubits, the processing elements of quantum computers by using pulsed microwave and millimeter-wave radiation to perform quantum operations on the spin states of these systems are being investigated. In the process, some important issues regarding the tunneling mechanism by which the magnetic moments of these systems reverse direction at temperatures below a few Kelvin are also investigated.A series of experiments are being performed to measure the effect of the applied radiation on the magnetic relaxation of the molecular magnets. These experiments include photon-assisted relaxation, which occurs when the radiation helps the molecule's spin reverse direction, Rabi oscillations of the probability of reversal with radiation-pulse duration, and free-precession of a quantum superposition of spin states produced by a series of radiation pulses. These experiments are aimed at providing a measure of the decoherence time of the excited spin state, a crucial parameter for determining whether the molecular magnets can be used as qubits. The project is also investigating methods of mitigating inhomogeneous broadening effects due to dipole interactions with neighboring molecules, nuclear spins and defects.The project has potential impacts for the fields of quantum computation and information storage. It is also promoting the education of undergraduate students, especially underrepresented groups like women and minorities.